Pump device



Oct. 22, 1957 Filed Feb. 12 1953 S. ENGLESSON PUMP DEVICE 3 Sheets-Sheet 1 Oct. 22, 1957 s. ENGLESSON 2,810,345

' PUMP DEVICE Filed Feb. 12, 1953 3 SheetsSheet 2 1957 s. ENGLESSON 2,81

PUMP DEVICE Filed Feb. 12, 1953 5 Sheets-Sheet 3 2,810,345 e Patented Oct. 22,1957

half to Aktiebolaget Flygts Pumpar, Stockholm, Swe- I den, a corporation of Sweden Application February 12, 1953, Serial No. 336,621 3 Claims. ((11. 103-4 It is already known in connection with pump systems, such as for instance hot water heating plants, to use a pair of separate pumps inserted in parallel in the circulation system with the object, in the event of possible failure of operation of one of said pumps, of allowing the system to operate under the control of the other pump. Preferably, in such known systems the pumps are arranged to operate alternately, so that for instance each pump operates during a period of a couple of weeks in order to secure uniform wear of both pumps. As a result, both pumps will have substantially the same life.

Hitherto, when two separate pumps are inserted in two parallel branches of a hot water circuit, shut-01f valves are provided on both sides of each'pump.

Such a pumping plant will necessarily occupy a large space and will be expensive and troublesome to handle, as there are four valves to be manually operated on shifting from one pump to another.

The present invention has for its main object to provide an improved pumping device including two alternately running pump units, which is extremely easy to handle.

According to the present invention two impellers, each having its own driving means, are arranged in a common housing provided with a-single outlet and a single inlet only, a valve housing being provided at the connection of the two branch channels leading to said impellers, said valve housing including a valve, which is adapted on operation of one impeller automatically to close the branch channel leading to the other impeller.

The invention will hereinafter be more fully described with reference to the accompanying drawings showing some preferred embodiments of the invention. Fig. 1 is an elevational view, partly in section, of a pump device according to the invention and Fig. 2 a plan view of the same device. Fig. 3 is a fragmentary sectional view of a valve housing taken substantially on broken line IIIIII of Fig. 1. Figs. 4 and 5 are an end view and a plan view partly in section respectively of a modified embodiment of the invention. Figs. 6 and 7 are fragmentary sectional views of modified embodiments of a valve housing located at the inlet side of a pump device. And Fig. 8 is a plan view, similar to Fig. 2, but showing a modification.

Referring now to Figs. 1 and 2, each of two casings 1 and 2 provided with circumferential flanges at one end thereof includes a motor driving an impeller, one impeller 20 of the casing 2 being shown in Fig. 2, preferably mounted on a stub shaft of said motor protruding through the end wall of the casing near said flange. The casings 1 and 2 are supported by corresponding parts 3 and 4 of a common housing for said impellers. Said housing is provided with a single inlet 5 and a single outlet 6 only. From said inlet 5 and outlet 6 respectively branch channels lead to the respective impellers. The junction of said branch channels and said inlet or outlet is arranged to form a valve housing 7 or 12 respectively, said housing including a valve adapted to close the branch channel to one impeller automatically when the other impeller is under operation as a result of the pressure produced. In

. 2 the embodiment according to Figs. 1, 2 and 3, a valve housing 7 is shown adjacent the outlet 6 at the junction between the two branch channels 8 and 9 leading from said impellers. In this case the valve suitably comprises a spherical valve member 10 adapted to engage alternately two valve seats 11 and 11 at the mouth of said branch channels 8 and 9 respectively. Between the said two seats is a countersink for receiving the ball 10 in an intermediate position where it permits the fluid to pass freely through both branch channels Sand 9.

In the embodiment shown in Figs. 1 and 2 the impellers are arranged side by side in the common housing with their axes parallel. However, it is to be noted that the invention is not restricted to that arrangement, but the impellers may face each other with their shaft lying along one .and the same axis as shown in'Figs. 4 and 5. The same reference numerals as in Figs. 1 and 2 are used for corresponding details. Furthermore, the inlet and outlet may be positioned at suitable points along the circumference of said housing of the pumping device.

A valve housing 12 (shown in Fig. 8), which according to the invention is positioned at the inlet 5, includes a valve as shown in Fig. 6, being a fragmentary sectional view of'said valve housing seen from below. The valve member consists of two rigidly connected flaps 13, 13' forming an angle with respect to each other, said valve member at the joint 14 of said flaps being pivotally mounted at the cross point of the branch channels 16 and 17 so that the said flaps 13, 13' may alternately engage the valve seats 15 and 15' at the mouth of the said branch channels 16 and 17 respectively. The valve memnel leading to the stationary impeller.

ber may occupy an intermediate position when both imber'may. thus be moved to engage either of said valve seats 15 and 15 as a result of the suction and pressure action on respective flaps 13 and 13' produced by the impeller under'operation, thereby closing the branch chanpellers are running, thereby permitting the fluid to pass through both branch channels without any appreciable resistance.

Said rigidly connected flaps 13,13 may be replaced by separate flaps or balls 18, 18 (Fig. 7). In the latter case lips 19 are provided for limiting the backward move- 1 ment of said balls 18, 18.

The operation is as follows: When either of said impellers is caused to run, for instance that supported by the casing 1, the ball 10 (or the flap 13), if it has previously engaged the seat 11 (or 15) or taken up an intermediate position, will be caused to engage the other seat 11 (or 15') as a result of the positive pressure produced in the branch channel 8 (or 17) and the negative pressure produced in the branch channel 16, 9 by said impeller under operation. The fluid may thus flow through the running impeller, while the channel through the other impeller which remains stationary is closed. Said latter positions of the valve members are shown in full lines in Figs. 3 and 6.

An intermediate position and an initial position of the ball 10 are shown in broken lines inFig. 3. When the impeller supported by the casing 1 is brought to a standstill and the other impeller is caused to run, the ball 10 (or the flap 13) is urged to engage the opposite valve seat 11 (or 15) as a result of the positive pressure produced in the branch channel 9 and the negative pressure produced in the branch channel 17.

The conditions are analogous when the valve consists of two separate balls 18 and 18' (Fig. 7), said balls performing corresponding movements owing to the positive and negative pressure produced by the running impeller in the channel leading through the stationary impeller and the channel leading through the impeller under operation respectively. Said balls are preferably arranged to take The valve memup positions spaced seats when both pumps are stationary, thereby fluid to freely through both impellers. Similarly, both balls 18, 18 take up the same positions when'both impellers are running.

ny order tea-facilitate she mounting-of the/valve, satd common housing may be divido'eladjacentsaid valve/hone 1 ing, theparts'being secured-together ajsby means of I or the like. Preferably said commQn honsing-"is divided along the line. VII-VII in Fig. 7 in order to render, it possible to insert the balls 18,-18f. v

Thus, in allcases the branch'channel through the stationary impeller will be automatically closed to prevent a back-flowtherethrough I Consequently no manual operation of valves will be necessary on shifting from one impeller-to another The impellers and their driving motors are assembled inseparatc' units, which may easily be dismounted from .the commonpumping housing independent of each other inorden to replacea new similar unit.

On disconnection of the pumping device for repairs of the replacement of new parts only two shut-off valves need be operated, whereas previously four valves were,

necessary.

What I claim is:

1. In a compact centrifugaltwin pump device, for use in connection with two separate shaft borne separately powered impellers, in combination, a body forming an integral casing defining two separate chambers side by side in the sameplane, each chamber adapted to receive one of said impellers, said body having a single inlet and a single discharge opening, branch channels formed within said casing and connecting each of said chambers with said inlet opening and discharge opening respectively, valve means disposed within said casing and movable between two opposite positions blocking in either position one branch channel and opening the other for controlling the communication between one of said openings and the respective branch channels, and two separate upright supports each including an impeller andmotor and each individuallyremovably fastened on the body casing above a chamber.

2. A compact centrifugal twin pump unit comprising,

in combination, a substantially flat hollow base structure having a single inlet and a single discharge opening, two pairs of branch channels formed in said base structure and connecting each of said openings with two laterally spaced separate volute chambers formed in said base structure and open at the fiat top surface thereof, valve members at the junction of one pair of said branch channels movable between two opposite positions blocking in each position a branch channel and unblocking the other for controlling the communication between said branch channels and the respective opening, two supports removably mounted upon said flat top surface at right angles thereto so as to cover the openingo f the respective chamber, a pump wheel in each chamber and rotatably carried by said support, and a motor mounted in each support for driving said pump wheel each pump wheel and motor forming a unit with its support removably exchangeable on said base structure.

3. A compact centrifugal twin pump unit comprising,

-in combination, a substantially flat hollow base structure spaced separate volute chambers formed in said base struc:

ture and open at the flat top surface thereof, valve members at the junction of one pair of said branch channels movable between two opposite positions blocking in each position a. branch channel and unblocking the other tor controlling the communication between said branch channels and the respective opening, two supports removably mounted upon said flat top surface at right angles thereto so as to cover the opening of the respective chamber, a purnp wheel in eachchamber the diameter of which is less than the diameter of the opening of the respective chamber, a motor mounted in each support, a driving shaft connecting said motor with said pump wheel and extending through said supports for carrying said pump wheel so as to allow removing each support and its associated motor and pump wheel as a unit from the base structure.

References Cited in the file of this patent UNITED STATES PATENTS 

